To participate as a member of Acute Leukemia Group B (1) studying the natural history of these diseases as modified by various experimental therapeutic regimens, (2) to determine effect, extent, and duration of remissions obtained, (3) to determine the relative efficacy of the various agents used, and (4) to promote the best possible treatment of these disorders. To establish and maintain a laboratory where the serum and urinary proteins of patients with multiple myeloma and related conditions being studied by various members of the Acute Leukemia Group B may be typed and stored for future reference. Correlations will be made between the types of proteins found in each patient and the effectiveness of specific chemotherapeutic agents.